This invention relates to input devices for computer-related apparatus, and, more particularly, to an improved ergonomic touchpad for use in conjunction with such apparatus.
Touchpads or touch screens often serve the same input and navigation functions in computers as the so-called xe2x80x9cmouse.xe2x80x9d Touchpads generally include a planar, generally rectangular input surface and a pair of control keys below the input surface. The input surface of the touchpad generally has capacitive or resistive sensors or other means for detecting the presence of a fingertip or other pointing object against or near the surface.
To perform the functions typically associated with a mouse, the user moves a stylus or his or her finger about the input screen which generally causes a cursor to move to corresponding positions on the display screen of a computer or computer-related apparatus. Tapping the display screen itself may correspond to xe2x80x9cclickingxe2x80x9d of a mouse button, thus selecting an element or command at which the cursor is positioned. Alternately, the two control keys of the touchpad can be used to select objects or commands, and the input surface can be used to drag or relocate the cursor in combination with the activation of the control keys.
Touchpads are especially prevalent in portable computers or other applications where it is uncertain whether a flat surface suitable for operating a mouse will be available. Increasingly, however, touchpads are available as add-on features or integral components of standard computer keyboards. U.S. Pat. No. D375,492 shows one such touchpad integrated into the chassis of a full-sized keyboard for a stand-alone computer.
Touchpads are often located below associated keyboards or keypads, that is, when the keypad is positioned for normal operation by the user, the touchpad is located between the user and the keypad or keyboard. If the keyboard is suitably close to the touchpad, the user can extend a finger from the keyboard, generally the thumb from the spacebar, and contact the touchpad with the finger. This arrangement, while it has the advantage of potentially keeping the user""s hands in a normal typing position while accessing the touchpad, has various drawbacks and disadvantages. Chief among the drawbacks is the following: normal operations on the keyboard involve rapid and frequent movements and xe2x80x9creaches,xe2x80x9d especially when alphanumeric data is being entered. It is natural during operation of the keypad or keyboard by the user""s typing fingers for the user""s thumb to also involuntarily shift position during the course of such operation. Sometimes, inadvertent movements of the thumb during operation of the main keyboard cause the thumb to unintentionally contact the touchpad, thus performing an unintended operation in the course of another application.
Such unintended activation of the touchpad may open windows or execute time-consuming commands, both of which would interrupt the currently-displayed application. The execution of such commands or the opening of such windows is, at best, an inconvenience when operating a standard, stand-alone personal computer or when working with a state-of-the-art workstation. The unwanted execution of additional commands and the unintentional opening of additional windows can be even more frustrating when it occurs in the context of a portable personal computer running on batteries, where execution times are often slowed due to power constraints.
The space constraints on the keyboard and on the other input controls of a portable computer often require the touchpad to be located even closer to the user""s hands, particularly to his or her thumbs. As such, the opportunity for inadvertent touchpad activation is greatest in those computer environments, i.e., portable computers, in which touchpads are most prevalent.
Inadvertent activation of the touchpad is more likely to occur when the user is typing furiously or otherwise working rapidly with the main keyboard. During such power typing or rapid data entry, it is often the case that the user is focusing the majority of his or her attention on the data to be inputted, rather than on the display screen. Under such circumstances, inadvertent activation of the touchpad may not be detected for long periods of time, if ever. When the display is not being watched, even a seemingly harmless, unintentional command, like relocating the cursor, can have drastic consequences. Only when the user has finished his or her task and is proofreading or otherwise reviewing the final product will the user be confronted with inexplicable data corruption, including data loss, random insertions, or scrambling of data, all of which occurred during the course of seemingly normal operation of the keyboard. Such occurrences are obviously not only a waste of time, but can border on the infuriating, especially when combined with the time pressures which required the fast-paced data entry to begin with.
One way of avoiding the above-described drawbacks is to distance the touchpad from the keyboard or other input device. Such a solution, however, vitiates the advantages of the user""s being able to access the touchpad without needing to remove his or her hands from the keyboard. Thus, operation of such a xe2x80x9cremotexe2x80x9d touchpad is more time-consuming than need be, requiring the user to interrupt the flow of text or data entry being accomplished on the main keyboard. Furthermore, it is not always possible for a user to distance the touchpad from the keyboard, such as with a portable computer, or when the touchpad is otherwise integral with the keyboard.
The increasing prevalence of portable computers means that they are more likely to be carried and used in low-light situations. Because touchpads of the current art are generally in substantially the same plane as the working surfaces of the keyboard chassis, it is sometimes not easy for a user""s fingers to locate touchpads in reduced-light situations. This, again, makes operation of the associated computer more difficult in such environments.
There is thus a need to improve the ergonomics of touchpads used in association with keypads, keyboards or other input devices.
There is a corresponding need to optimize the location of the touchpad so it can be accessed during normal operation of a keypad, but without undesirable, unintended activation of such touchpad.
An input device has a touchpad located near a corresponding keyboard. The touchpad has a ridge protruding from the plane of the touchpad and extending near the edge of the touchpad. The touchpad is located relative to the keyboard so that the ridge is likely to be encountered by the user""s fingers nearest the touchpad, typically the thumbs. As such, the ridge provides tactile feedback, that is, the ridge signals the boundary of the touchpad either to facilitate its activation or to inhibit inadvertent activation thereof.
In one aspect of the invention, the likely locations of the user""s thumbs during operation of the keyboard define a first ergonomic zone, while the xe2x80x9creachxe2x80x9d of the user""s thumbs when other fingers are in position over the keyboard constitutes a second ergonomic zone. There is an overlap in the boundaries of these two ergonomic zones and the touchpad is located so that its edge extends at least partially within this overlap zone. In this way, the ridge of the present invention and its advantageous signaling functions are likely to be encountered during normal operations of the input control device.
In accordance with still another aspect of the current invention, the touchpad is either rectangular or triangular. The touchpad can be integrally mounted with the associated keyboard in a chassis.
In yet another aspect of the present invention, the touchpad is part of a portable computer.